Screw holding screw driver



28, 1950 B. J. JOHNSON 2,531, 1

SCREW HOLDING SCREW DRIVER Filed April 26, 1946 mmvrm -Zemue J .JoivmsonWM, J W

A7" TOR/V522) Patented Nov. 28 1950 UNITED STATES PATENT OFFICE SCREWHOLDING SCREW DRIVER Bennie J. Johnson, Bridgeport, Conn.

Application April 26, 1946,"Serial N'o.1565,123

5 Claims. V2 .Ei

This invention relates to screw drivers.

An object of the invention is to provide an improved screw driver havingsimpl and economy cal-toe1nanuiacture retaining means for holding ascrew on the bit prior to insertion of the screw.

A feature of the invention is the provision of a screw-retaining meanswhich may be swung to and .resilientlyheld in an inoperative position A.it is desiredto use the screw driver without the said means beingoperative.

Another feature of the invention is the provision .of a screw driver andscrew-retaining means in which :the latter may be adiusted to vary thetension or pressure by which the screw is held on the bit.

Other features and advantages will hereinafter appear.

In theaccompanying drawings:

Fig. 1 isa-side elevation of theirnproved screw driver of the .presentinvention, with the screwretaining means in extendedor operativeposition.

Fig. 2 is a fragmentary side elevation showing thebit portion of thescrew driver, and showing a screw beingheld in place prior to insertion.

Fig. 3 is a longitudinal section'through the bit portion of the screwdriver.

4 is a fragmentary broadside view of the bit and screw-retaining .meansof the screw driver.

.5 is a fragmentary-side elevation showing the-bit portion or" the screwdriver, and showingthe screw-retaining means shifted to retract ed orinoperative position.

Fig. 6 a fragmentary longitudinal section through the bit portion of ascrew driver illustrating a niocification of the invention, and

Fig. 7 is an enlarged fragmentary view of the tip portion of the screwdriver of Fig. 1.

As shown, the improved screw driver of the present invention comprises ashank 58 having at one end a handle it and at the other end aflattapered bit portion i2. A resilient blade or fiat spring 13is-secured to the bit portion it of the screw driver, the said springbeing-preferably of spring steel and having'intermediate its ends anaperture for receiving a screw is which is threaded into-the bit portion42 and is'locked therein by a lock nut i5.

The fiat spring 83 has adjacent its'iorward end it a curved portion Hwhich extends toward the flat surface lil'of the bit portion l21andengages the latter. The other end 19 of the spring i3'is bent so as toalso engagethebitportion L2 or ointed end. A detent is'thus formedbyennt of the end i9 with the bore or recess 2:, and preferably the edgeof the said ".recess isnotbeveled but-is made sharp so that it tends tobite into the end L9.

The flat spring '53 is supportedin its operativnpositienshown in "Fig.21 under a slight tension, .as imposed by the screw :14. While thistension does not have any considerable magni tude it is sufficienhinconjunction-withthe sharp o'fthe recess 2 l to'requirethat a fairlysubstantial pressure be exerted on the spring to swing or swivel thelatter about the screw 14. By this organization, therefore, the springwill be securely held against accidentaldislodgement from its operativeposition under :normal conditions of 'use.

Preferably'the end It of the fiat spring l3is madezto extend'cr projectslightly beyond the "extreme tip 22a of the shank portion 12, 'asishown.in'Fi'gs. 1 and2,iand the said tip'is slabbedat 22 to reduce itsthickness slightly.

In operation, the .screw driver of this invention is applied to theslotteds'head of a screw'such as that shownat '23, Fig. 2, by firstengaging the end it of the spring with the face 23a of the screwhead andthen shifting the screw driver shank so as to cause the said end topartially enter the slot of the head, the slabbed tipi l2a of the bitportion not, however, immediatelyentering the slot due to a space. 26aexistingbetween the tip IZaand the spring end H3. The screw driver shankH0 is then shifted laterally to cause lateralpressure on the end'lG ofthe spring, flexing the latter and reducing the amount 'of the space29a, whereupon it will be found that the slabbed tip 12a of the bitportion is brought in position to fully enter the slot ofthe screwhead.During this'latter operation the flexure of "the spring It takesplacemainly in the curved portion i=1 thereof.

In applying the screw driverto-a screw in "the manner described above,the operationisxiacilitated if the "tip l 2a has a bevel 12b, -:as shownin Fig. '7, to enable the tip portion to easily slide over the head ofthe screw without cutting into the latter.

The slabbed tip l2a of the screw driver and the end I B of the springwhen extending into the slot of the screwhead will exert a substantialoutward pressure on the walls of the slot, and will securely retain thescrew on the bit portion I2 of the driver.

It will be noted that, due to the novel shape of the spring l3,tightening of the screw I4 will cause a decrease in the space betweenthe spring and the shank portion [2, and an increase in the space 20a,and this is an important feature of the invention since it enables thegripping force of the tip lZa, and end It of the spring to be varied tosuit difierent conditions of use and different sizes of screws.

Where large screws are to be handled, the pivot screw It may be drivenfurther into the bit portion [2 so as to increase the separation orspace 20a, and where small screws are to be handled, the pivot screw Imay be unscrewed Slightly, decreasing the space 20a. It will beunderstood that the gripping force exerted by the end 16 of the springI3 generally varies directly with the spacing 20a between the said endand the tip l2a of the bit portion l2. After each adjustment of thepivot screw M the lock nut I5 is again tightened so as to securely holdthe screw in its newly adjusted position.

If it should be desired to use the screw driver without utilizing theretaining action of the spring I3, the latter may be pivoted about thescrew It and shifted to an inoperative position as shown in Fig. 5. Forthe purpose of yieldably holding the spring l3 in the said inoperativeposition the bit portion [2 of the screw driver is provided with asecond detent recess 24, adapted to receive the pointed end [9 ofthespring.

A modification of the invention is illustrated in Fig. 6. The bitportion illustrated therein has a pivot screw 26 threaded into the saidportion and locked by a lock nut 21. Carried under the head of the screw26 is a flat spring 28 having an elongate slot 29 through which thescrew extends, and having a curved portion 30 adjacent its forward end3|, the opposite end 32 of the spring being also curved inward, towardthe shank portion 25.

spring, and to prevent the latter from having pivotal movement about thescrew 26.

In Fig. 6, the spring 28 is shown in extended or operative position, andthe retracted or inoperative position is shown by dotted lines. It willbe understood that, by the provision of the slot 29 in the spring andthe slot 33 in the shank portion 25 of the screw driver, the spring 28is shiftable longitudinally between its extended and retractedpositions.

If desired, a pair of recesses 34 may be provided in the bottom of theslot 33 to accommodate the tip portion of the spring 28, the saidportion being then made pointed. By this arrangement the spring 28 willbe positively locked in either the extended or the retracted position.

As in the first described embodiment of the invention, the spring 28 isadjustable to vary the gripping force exerted in the slot of a screw--head, this being accomplished by turning the screw 26 either in or out.

Variations and modifications may be made within the scope of thisinvention and portions The said shank portion has a slot 33 in one faceto receive the end 32 of the fiat of the improvements may be usedwithout others.

Iclaim:

1. A screw driver having a spring arm overlying its bit portion with anintermediate portion and end portion thereof in spaced relation to thebit portion, the tip of the bit portion and the spaced end of the armbeing juxtaposed and insertable in the slot of a screw to grip thelatter and retain it on the bit portion; and adjustable means carried bythe bit and passing through the intermediate spaced part of the arm forsecuring the arm to the bit and for varying the gripping force exertedby the tip of the bit portion and the end of the arm on the screw slot,the said arm being pivotally movable on the bit portion to swing the endof the arm either adjacent the tip of the bit portion for engagementwith a screw, or away from the said tip to an inoperative non-screwengaging position.

2. In a screw driver, a spring arm pivotally secured, at a pointsubstantially midway between its ends, to the bit of the screw driver,one end and an intermediate portion of the said arm being bent lateralland engaging the said bit, the other end of the arm and the partintermediate the said bends being thereby spaced from the bit and thesaid other arm end and bit being juxtaposed and insertable in the slotof a screw to grip and retain the latter, the pivot for the arm passingthrough the intermediate portion and being adjustable to vary thespacing between the bit and said intermediate portion and the said otherend of the arm, thereby to adjust the gripping force of the said bit andarm end on the screw; and means including a recess on the bit and aprojection on the arm, entering the said recess, for yieldably holdingthe arm in operative position, the said arm when pivotally moveddisplacing the said projection from the said recess and separating anddisassociating the screw-engaging end of the arm from the screwengagingportion of the bit.

3. A screw driver having a spring arm secured to its bit, one end and onintermediate portion of the said arm being bent laterally and engagingthe said bit, the other end of the arm and the part intermediate thesaid bends being thereby spaced from the bit and the said other arm endand bit being juxtaposed and insertable in the slot of a screw to gripand retain the latter; means carried by the bit and passing through anopening in the part of the arm intermediate said bends and securing thelatter to the bit, for varying the spacing between the bit and the saidother end of the arm, thereb to adjust the gripping force of the saidbit and arm end on the screw; said opening in the arm extendinglongitudinally and enabling the arm to have longitudinal movement n thebit between an extended operative position, and a retracted inoperativeposition wherein the screw-engaging end of the arm is separated anddisassociated from the screw-engaging part of the bit; and meansincluding a slot in the bit and a portion on the bit-engaging end f thearm entering the said slot, for guiding the arm to either operative orinoperative position and means in the slot cooperating with said end forholding the arm against shifting when in the said positions.

4. A screw driver having a spring arm overlying its bit portion with oneend portion and intermediate portion of said arm in spaced relationtherewith, the tip of the bit portion and said one end of the arm beingjuxtaposed and insertable in the slot of a screw to grip the lat.

ter and retain it on the bit portion; and adjustable screw means carriedby the bit and passing through the intermediate portion of the arm forsecuring the arm to the bit and varying the spacing between the bitportion and the spaced end of the spring arm for increasing ordecreasing the ripping force exerted on the screw by the said tip of thebit portion and end of the arm.

5. In a screw driver, a spring arm, pivot means securing said arm, at apoint substantially midway between its ends, to the bit of the screwdriver, one end and an intermediate portion of the said arm on oppositesides of said pivot means being bent laterally and engaging the said,

bit, the other end of the arm and the part of the arm intermediate thesaid bend and first end of the arm being thereby spaced from the bitwith the other end of said arm and the end of the bit being juxtaposedand insertable in the slot of a screw to grip and retain the latter; andmeans including a recess in the bit and a projection on the arm,entering the said recess, for

BENNIE J. JOHNSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 532,830 Snyder Jan. 22, 18951,178,141 Eckman Apr. 4, 1916 1,392,796 Reinhalter Oct. 4, 1921

